Arrived to do a performance maintenance. Set system for cooling. Measured the systems static pressure measured a temperature split between return and supply air. Found that the system is operating with failing static pressure. Checked interior of the furnace for cleanliness. Found that the blower wheel is heavily coated in dust debris. Went outside and verified refrigerant levels. Verified operation of all electronic and mechanical components. Found that the capacitor for the condenser is failing. Rinsed coil free of debris. Spoke with homeowner about the system. Air conditioning system is operational at this time.